import

qemu/util/host-utils.c

@@ -0,0 +1,167 @@
+/*
+ * Utility compute operations used by translated code.
+ *
+ * Copyright (c) 2003 Fabrice Bellard
+ * Copyright (c) 2007 Aurelien Jarno
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <stdlib.h>
+#include <stdint.h>
+#include "qemu/host-utils.h"
+
+#ifndef CONFIG_INT128
+/* Long integer helpers */
+static inline void mul64(uint64_t *plow, uint64_t *phigh,
+                         uint64_t a, uint64_t b)
+{
+    typedef union {
+        uint64_t ll;
+        struct {
+#ifdef HOST_WORDS_BIGENDIAN
+            uint32_t high, low;
+#else
+            uint32_t low, high;
+#endif
+        } l;
+    } LL;
+    LL rl, rm, rn, rh, a0, b0;
+    uint64_t c;
+
+    a0.ll = a;
+    b0.ll = b;
+
+    rl.ll = (uint64_t)a0.l.low * b0.l.low;
+    rm.ll = (uint64_t)a0.l.low * b0.l.high;
+    rn.ll = (uint64_t)a0.l.high * b0.l.low;
+    rh.ll = (uint64_t)a0.l.high * b0.l.high;
+
+    c = (uint64_t)rl.l.high + rm.l.low + rn.l.low;
+    rl.l.high = c;
+    c >>= 32;
+    c = c + rm.l.high + rn.l.high + rh.l.low;
+    rh.l.low = c;
+    rh.l.high += (uint32_t)(c >> 32);
+
+    *plow = rl.ll;
+    *phigh = rh.ll;
+}
+
+/* Unsigned 64x64 -> 128 multiplication */
+void mulu64 (uint64_t *plow, uint64_t *phigh, uint64_t a, uint64_t b)
+{
+    mul64(plow, phigh, a, b);
+}
+
+/* Signed 64x64 -> 128 multiplication */
+void muls64 (uint64_t *plow, uint64_t *phigh, int64_t a, int64_t b)
+{
+    uint64_t rh;
+
+    mul64(plow, &rh, a, b);
+
+    /* Adjust for signs.  */
+    if (b < 0) {
+        rh -= a;
+    }
+    if (a < 0) {
+        rh -= b;
+    }
+    *phigh = rh;
+}
+
+/* Unsigned 128x64 division.  Returns 1 if overflow (divide by zero or */
+/* quotient exceeds 64 bits).  Otherwise returns quotient via plow and */
+/* remainder via phigh. */
+int divu128(uint64_t *plow, uint64_t *phigh, uint64_t divisor)
+{
+    uint64_t dhi = *phigh;
+    uint64_t dlo = *plow;
+    unsigned i;
+    uint64_t carry = 0;
+
+    if (divisor == 0) {
+        return 1;
+    } else if (dhi == 0) {
+        *plow  = dlo / divisor;
+        *phigh = dlo % divisor;
+        return 0;
+    } else if (dhi > divisor) {
+        return 1;
+    } else {
+
+        for (i = 0; i < 64; i++) {
+            carry = dhi >> 63;
+            dhi = (dhi << 1) | (dlo >> 63);
+            if (carry || (dhi >= divisor)) {
+                dhi -= divisor;
+                carry = 1;
+            } else {
+                carry = 0;
+            }
+            dlo = (dlo << 1) | carry;
+        }
+
+        *plow = dlo;
+        *phigh = dhi;
+        return 0;
+    }
+}
+
+int divs128(int64_t *plow, int64_t *phigh, int64_t divisor)
+{
+    int sgn_dvdnd = *phigh < 0;
+    int sgn_divsr = divisor < 0;
+    int overflow = 0;
+
+    if (sgn_dvdnd) {
+        *plow = ~(*plow);
+        *phigh = ~(*phigh);
+        if (*plow == (int64_t)-1) {
+            *plow = 0;
+            (*phigh)++;
+         } else {
+            (*plow)++;
+         }
+    }
+
+    if (sgn_divsr) {
+        divisor = 0 - divisor;
+    }
+
+    overflow = divu128((uint64_t *)plow, (uint64_t *)phigh, (uint64_t)divisor);
+
+    if (sgn_dvdnd  ^ sgn_divsr) {
+        *plow = 0 - *plow;
+    }
+
+    if (!overflow) {
+        if ((*plow < 0) ^ (sgn_dvdnd ^ sgn_divsr)) {
+            overflow = 1;
+        }
+    }
+
+    return overflow;
+}
+#else
+// avoid empty object file
+void dummy_func(void);
+void dummy_func(void) {}
+#endif